[RFC 15/23] ARM: LPAE: allow proc override of TTB setup
From: Cyril Chemparathy
Date: Mon Jul 23 2012 - 21:10:46 EST
This patch allows ARM processor setup functions (*_setup in proc-*.S) to
indicate that the page table has already been programmed. This is
done by setting r4 (page table pointer) to -1 before returning from the
processor setup handler.
This capability is particularly needed on LPAE systems, where the translation
table base needs to be programmed differently with 64-bit control
register operations.
Further, a few of the processors (arm1026, mohawk, xsc3) were programming the
TTB twice. This patch prevents the main head.S code from programming TTB the
second time on these machines.
Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>
Signed-off-by: Vitaly Andrianov <vitalya@xxxxxx>
---
arch/arm/kernel/head.S | 11 ++++++-----
arch/arm/mm/proc-arm1026.S | 1 +
arch/arm/mm/proc-mohawk.S | 1 +
arch/arm/mm/proc-v6.S | 2 ++
arch/arm/mm/proc-v7-2level.S | 3 ++-
arch/arm/mm/proc-v7-3level.S | 1 +
arch/arm/mm/proc-v7.S | 1 +
arch/arm/mm/proc-xsc3.S | 1 +
8 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 835898e..692e57f 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -411,17 +411,18 @@ __enable_mmu:
#ifdef CONFIG_CPU_ICACHE_DISABLE
bic r0, r0, #CR_I
#endif
-#ifdef CONFIG_ARM_LPAE
- mov r5, #0
- mcrr p15, 0, r4, r5, c2 @ load TTBR0
-#else
+#ifndef CONFIG_ARM_LPAE
mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT))
mcr p15, 0, r5, c3, c0, 0 @ load domain access register
- mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
#endif
+
+ @ has the processor setup already programmed the page table pointer?
+ adds r5, r4, #1
+ beq __turn_mmu_on @ yes!
+ mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
b __turn_mmu_on
ENDPROC(__enable_mmu)
diff --git a/arch/arm/mm/proc-arm1026.S b/arch/arm/mm/proc-arm1026.S
index fbc1d5f..c28070e 100644
--- a/arch/arm/mm/proc-arm1026.S
+++ b/arch/arm/mm/proc-arm1026.S
@@ -404,6 +404,7 @@ __arm1026_setup:
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
mcr p15, 0, r4, c2, c0 @ load page table pointer
+ mvn r4, #0 @ do not set page table pointer
#endif
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mov r0, #4 @ explicitly disable writeback
diff --git a/arch/arm/mm/proc-mohawk.S b/arch/arm/mm/proc-mohawk.S
index fbb2124..a26303c 100644
--- a/arch/arm/mm/proc-mohawk.S
+++ b/arch/arm/mm/proc-mohawk.S
@@ -390,6 +390,7 @@ __mohawk_setup:
mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs
orr r4, r4, #0x18 @ cache the page table in L2
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
+ mvn r4, #0 @ do not set page table pointer
mov r0, #0 @ don't allow CP access
mcr p15, 0, r0, c15, c1, 0 @ write CP access register
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 566c658..872156e 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -210,7 +210,9 @@ __v6_setup:
ALT_UP(orr r4, r4, #TTB_FLAGS_UP)
ALT_SMP(orr r8, r8, #TTB_FLAGS_SMP)
ALT_UP(orr r8, r8, #TTB_FLAGS_UP)
+ mcr p15, 0, r4, c2, c0, 0 @ load TTB0
mcr p15, 0, r8, c2, c0, 1 @ load TTB1
+ mvn r4, #0 @ do not set page table pointer
#endif /* CONFIG_MMU */
adr r5, v6_crval
ldmia r5, {r5, r6}
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index 3397803..cc78c0c 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -139,7 +139,7 @@ ENDPROC(cpu_v7_set_pte_ext)
/*
* Macro for setting up the TTBRx and TTBCR registers.
- * - \ttb0 and \ttb1 updated with the corresponding flags.
+ * - \ttbr0 and \ttbr1 updated with the corresponding flags.
*/
.macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp
mcr p15, 0, \zero, c2, c0, 2 @ TTB control register
@@ -147,6 +147,7 @@ ENDPROC(cpu_v7_set_pte_ext)
ALT_UP(orr \ttbr0, \ttbr0, #TTB_FLAGS_UP)
ALT_SMP(orr \ttbr1, \ttbr1, #TTB_FLAGS_SMP)
ALT_UP(orr \ttbr1, \ttbr1, #TTB_FLAGS_UP)
+ mcr p15, 0, \ttbr0, c2, c0, 0 @ load TTB0
mcr p15, 0, \ttbr1, c2, c0, 1 @ load TTB1
.endm
diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
index 3b1a745..5e3bed1 100644
--- a/arch/arm/mm/proc-v7-3level.S
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -124,6 +124,7 @@ ENDPROC(cpu_v7_set_pte_ext)
mcr p15, 0, \tmp, c2, c0, 2 @ TTBCR
addls \ttbr1, \ttbr1, #TTBR1_OFFSET
mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
+ mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0
.endm
__CPUINIT
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index c2e2b66..8850194 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -250,6 +250,7 @@ __v7_setup:
#ifdef CONFIG_MMU
mcr p15, 0, r10, c8, c7, 0 @ invalidate I + D TLBs
v7_ttb_setup r10, r4, r8, r5 @ TTBCR, TTBRx setup
+ mvn r4, #0 @ do not set page table pointer
ldr r5, =PRRR @ PRRR
ldr r6, =NMRR @ NMRR
mcr p15, 0, r5, c10, c2, 0 @ write PRRR
diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S
index b0d5786..db3836b 100644
--- a/arch/arm/mm/proc-xsc3.S
+++ b/arch/arm/mm/proc-xsc3.S
@@ -455,6 +455,7 @@ __xsc3_setup:
mcr p15, 0, ip, c8, c7, 0 @ invalidate I and D TLBs
orr r4, r4, #0x18 @ cache the page table in L2
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
+ mvn r4, #0 @ do not set page table pointer
mov r0, #1 << 6 @ cp6 access for early sched_clock
mcr p15, 0, r0, c15, c1, 0 @ write CP access register
--
1.7.9.5
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